Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P47989 (xanthine oxidase)
 8,633 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A blotting method is described to detect enzymes that do not normally yield a colored product. The method can be used for dot blotting as well as blotting after gel electrophoresis of many enzymes if the reactions they catalyze can be coupled to an oxidase or a dehydrogenase. The latter, designated "auxiliary enzymes," are preimmobilized on membranes of nitrocellulose or positively charged nylon and the reaction they catalyze is coupled with reduction of tetrazolium salt to yield colored formazan on areas of the transfer membrane occupied by the blotted enzymes. In the examples reported here, preimmobilized glucose oxidase, L-amino acid oxidase, xanthine oxidase, malate dehydrogenase, and a mixture of hexokinase and glucose-6-phosphate dehydrogenase were used as auxiliary enzymes to detect blotted invertase, leucine aminopeptidase, purine nucleoside phosphorylase, fumarase, and adenylate kinase, respectively. Detection limits varied, but never exceeded 100 ng for these enzymes. After blotting from polyacrylamide gels, the fumarase assay was the most sensitive of those investigated, detecting 10 ng of enzyme used for electrophoresis. Invertase, a glycoprotein, was detected with higher sensitivity on nitrocellulose membranes when concanavalin A was present on the membrane in addition to the auxiliary enzyme, glucose oxidase. On blots from isoelectric focusing gels, the assay detected two isozymes of purine nucleoside phosphorylase in a sample from calf spleen and at least five isozymes of this enzyme in lysates from human red cells.
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PMID:Activity staining of blotted enzymes by reaction coupling with transfer membrane-immobilized auxiliary enzymes. 245 38

The dose dependent effect of superoxide dismutase in providing protection against oxygen free radicals mediated tissue damage was investigated. Xanthine-xanthine oxidase system was used to generate oxygen free radicals in vitro and damage renal brush border membrane of mice. At lower concentrations, superoxide dismutase was found to rather aggravate renal brush border membrane damage as shown by significant increase (p less than 0.05) in the malondialdehyde levels and corresponding decrease (p less than .05) in the activities of marker enzymes of renal tissue injury i.e. alkaline phosphatase, gamma-glutamyl transpeptidase and leucine aminopeptidase except maltase whose activity increased correspondingly. At higher doses of superoxide dismutase, significant protection (p less than .05) was observed against tissue damage in a dose dependent manner. On the other hand, catalase and mannitol provided dose dependent protection and their combinations with superoxide dismutase could alleviate the enhanced tissue damage produced by lower doses of superoxide dismutase. The implications of these findings have been discussed.
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PMID:Concentration dependent function of superoxide dismutase in oxygen free radicals mediated tissue injury in renal brush border membrane. 281 3